INVESTMENT SECURITIES

The following table presents the amortized cost and fair value of the investment securities portfolio as of the dates indicated:



	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(In thousands)
March 31, 2017
Securities held-to-maturity:
Corporate bonds	$	240,304	$	13,722	$	—		$	254,026
Collateralized loan obligations	317,223		1,484		(70		)	318,637
Commercial mortgage-backed securities	305,742		2,887		(1,394		)	307,235
Total securities held-to-maturity	$	863,269	$	18,093	$	(1,464	)	$	879,898
Securities available-for-sale:
SBA loan pool securities	$	1,138	$	7	$	—		$	1,145
Private label residential mortgage-backed securities	121,214		16		(4,473		)	116,757
Corporate bonds	19,134		105		(95		)	19,144
Collateralized loan obligation	1,489,865		12,581		(193		)	1,502,253
Agency mortgage-backed securities	819,800		8		(24,566		)	795,242
Total securities available-for-sale	$	2,451,151	$	12,717	$	(29,327	)	$	2,434,541
December 31, 2016
Securities held-to-maturity:
Corporate bonds	$	240,090	$	13,032	$	(91	)	$	253,031
Collateralized loan obligations	338,226		1,461		(61		)	339,626
Commercial mortgage-backed securities	305,918		2,949		(1,781		)	307,086
Total securities held-to-maturity	$	884,234	$	17,442	$	(1,933	)	$	899,743
Securities available-for-sale:
SBA loan pool securities	$	1,221	$	—	$	—		$	1,221
Private label residential mortgage-backed securities	121,397		18		(4,238		)	117,177
Corporate bonds	48,574		482		(108		)	48,948
Collateralized loan obligations	1,395,094		12,449		(674		)	1,406,869
Agency mortgage-backed securities	830,682		9		(23,418		)	807,273
Total securities available-for-sale	$	2,396,968	$	12,958	$	(28,438	)	$	2,381,488

The following table presents amortized cost and fair value of the held-to-maturity and available-for-sale investment securities portfolio by expected maturity. In the case of mortgage-backed securities, collateralized loan obligations, and SBA loan pool securities, expected maturities may differ from contractual maturities because borrowers generally have the right to call or prepay obligations with or without call or prepayment penalties. For that reason, mortgage-backed securities, collateralized loan obligations, and SBA loan pool securities are not included in the maturity categories.



	March 31, 2017
	Securities Held-To-Maturity				Securities Available-For-Sale
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
	(In thousands)
Maturity:
Within one year	$	—	$	—	$	—	$	—
One to five years	15,000		15,131		10,000		10,087
Five to ten years	225,304		238,895		9,134		9,057
Greater than ten years	—		—		—		—
Collateralized loan obligations, SBA loan pool, private label residential mortgage-backed, commercial mortgage-backed, and agency mortgage-backed securities	622,965		625,872		2,432,017		2,415,397
Total	$	863,269	$	879,898	$	2,451,151	$	2,434,541

At March 31, 2017 and December 31, 2016, there were no holdings of any one issuer, other than the U.S. Government and its agencies, in an amount greater than 10 percent of the Company's stockholders’ equity.

The following table presents proceeds from sales and calls of securities available-for-sale and the associated gross gains and losses realized through earnings upon the sales and calls of securities available-for-sale for the periods indicated:



	Three Months Ended
	March 31,
	2017		2016
	(In thousands)
Gross realized gains on sales and calls of securities available-for-sale	$	3,356	$	16,794
Gross realized losses on sales and calls of securities available-for-sale	—		(5		)
Net realized gains on sales and calls of securities available-for-sale	$	3,356	$	16,789
Proceeds from sales and calls of securities available-for-sale	$	378,539	$	2,247,421
Tax expense on sales and calls of securities available-for-sale	$	1,396	$	7,060

Investment securities with carrying values of $997.6 million and $581.8 million as of March 31, 2017 and December 31, 2016, respectively, were pledged to secure FHLB advances, public deposits, repurchase agreements, and for other purposes as required or permitted by law.

The following table summarizes the investment securities with unrealized losses by security type and length of time in a continuous unrealized loss position as of the dates indicated:



	Less Than 12 Months					12 Months or Longer					Total
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
	(In thousands)
March 31, 2017
Securities held-to-maturity:
Collateralized loan obligation	$	20,115	$	(8	)	$	56,085	$	(62	)	$	76,200	$	(70	)
Commercial mortgage-backed securities	69,826		(1,394		)	—		—			69,826		(1,394		)
Total securities held-to-maturity	$	89,941	$	(1,402	)	$	56,085	$	(62	)	$	146,026	$	(1,464	)
Securities available-for-sale:
Private label residential mortgage-backed securities	$	115,914	$	(4,473	)	$	177	$	—		$	116,091	$	(4,473	)
Corporate bonds	—		—			3,539		(95		)	3,539		(95		)
Collateralized loan obligations	94,620		(193		)	—		—			94,620		(193		)
Agency mortgage-backed securities	793,865		(24,557		)	593		(9		)	794,458		(24,566		)
Total securities available-for-sale	$	1,004,399	$	(29,223	)	$	4,309	$	(104	)	$	1,008,708	$	(29,327	)
December 31, 2016
Securities held-to-maturity:
Corporate bonds	$	9,907	$	(91	)	$	—	$	—		$	9,907	$	(91	)
Collateralized loan obligation	10,056		(6		)	56,095		(55		)	66,151		(61		)
Commercial mortgage-backed securities	60,221		(1,781		)	—		—			60,221		(1,781		)
Total securities held-to-maturity	$	80,184	$	(1,878	)	$	56,095	$	(55	)	$	136,279	$	(1,933	)
Securities available-for-sale:
SBA loan pool securities	$	1,221	$	—		$	—	$	—		$	1,221	$	—
Private label residential mortgage-backed securities	116,216		(4,238		)	230		—			116,446		(4,238		)
Corporate bonds	—		—			3,530		(108		)	3,530		(108		)
Collateralized loan obligations	187,592		(674		)	—		—			187,592		(674		)
Agency mortgage-backed securities	805,803		(23,410		)	760		(8		)	806,563		(23,418		)
Total securities available-for-sale	$	1,110,832	$	(28,322	)	$	4,520	$	(116	)	$	1,115,352	$	(28,438	)

The Company did not record other-than-temporary-impairment (OTTI) for investment securities for the three months ended March 31, 2017 or 2016.

At March 31, 2017, the Company’s securities available-for-sale portfolio consisted of 163 securities, 52 of which were in an unrealized loss position and securities held-to-maturity consisted of 84 securities, 16 of which were in an unrealized loss position. At December 31, 2016, the Company’s securities available-for-sale portfolio consisted of 161 securities, 59 of which were in an unrealized loss position and securities held-to-maturity consisted of 87 securities, 15 of which were in an unrealized loss position.

The fair value of securities held-to-maturity improved at March 31, 2017 mainly due to tighter credit spreads at March 31, 2017 and improvement in the economic sectors for the bond issuers. The fair value of securities available-for-sale declined slightly at March 31, 2017 mainly due to changes in market interest rates.

The Company monitors its securities portfolio to ensure it has adequate credit support. As of March 31, 2017, the Company believed there was no OTTI and did not have the intent to sell these securities and, for securities with amortized cost below fair value at March 31, 2017, it is not likely that it will be required to sell the securities before their anticipated recovery. The Company considers the lowest credit rating for identification of potential OTTI. As of March 31, 2017, all of the Company's investment securities in an unrealized loss position received an investment grade credit rating.